As coders, we are seeing more and more documentation of Type 2 NSTEMI. There have been differing opinions on how this should be coded; fortunately, we have some coding guidance to help us now.

What is a Type 2 NSTEMI?

A type 2 NSTEMI is secondary to ischemia from a supply-and-demand mismatch. Something other than coronary artery disease is contributing to this supply-and-demand mismatch. This type of MI is typically marked by non ST elevation. Some of these causes may be respiratory failure, renal failure, COPD, heart failure, severe anemia, hypotension/shock, severe infection, extremely fast or slow heart rate, and hypertension. These are just a few examples.

In diagnosing a Type 2 MI, the patient will have an elevated troponin level (that changes), no clinical features of a typical MI (Type 1), and a clinical condition that is known to increase the oxygen demand or decrease the oxygen supply (see listed above). Treatment for a Type 2 MI consists of treating the underlying cause/condition. Once this is corrected the insult to the heart should improve/resolve.

How is a Type 2 acute MI coded in ICD-10-CM?

Unless a Type 2 MI is specifically documented to be a STEMI this would be coded as NSTEMI and reported with I21.4 per Coding Clinic, First Quarter 2017 page 44 until 10/1/2017.

Beginning FY2018 on October 1, 2017, a new code is available for MI Type 2 or MI due to demand ischemia I21.A1, Myocardial infarction type 2. In addition, other new codes are available for MI Types 3, 4a-c, and 5, I21.A9, Other myocardial infarction type.

Happy Coding!

The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.